It is well known that pilots and/or navigators must correctly and efficiently evaluate their pre-flight plans and/or current flight information as their lives and/or the lives of their passengers depend on the pilots accuracy and thorough planning. It is therefore desirous to provide a pilot and/or navigator with a new navigational aid specifically designed to improve and encourage pre-planning and/or current flight plan calculating. Nowhere in the prior art (known to the applicants) do they provide such a display means which is specifically designed for use by a navigator. However, several references have attempted to provide display means for various articles, such as maps, stamps, etc. and each of which include a transparent cover and/or overlay, such as U.S. Pat. No. 5,022,170, in which they teach a "WORK SURFACE INFORMATION DISPLAY PAD". The pad comprising a transparent cover over a base layer and a work surface, such as a work table or the like, as the bottom surface of the pad is textured so as to reduce slippage of the pad when on the work surface and the top surface of the pad is textured so as to provide a substitute work surface upon which to write or operate a computer mouse. A further attempt is disclosed in U.S. Pat. No. 4,157,626 in which they provide a "MAPS AND CHART HOLDER". The holder having on each of its end portions a container, with the containers being of a shape and size to accept and capture a continuous rolled document. The end containers allow the document to be rolled until the desired information is displayed upon a planar central region between the end containers. Still a further attempt is taught within U.S. Pat. No. 4,083,137 in which they provide a "DISPLAY SYSTEM ADAPTED FOR PHILATELIC MATERIALS". This display system substantially comprising an opaque base having an overlying transparent cover which is removably affixed to the base by adhesive. The base providing attachment zones for receiving philatelic materials such as stamps, while the transparent cover includes further related indicia, whereby, the base and cover in combination provide the display system.
Many devices, too numerous to mention, have been devised for holding a document which enables visual inspection of the document when the document is secured to the holding device. Springboards, clipboards and various variations thereof have been known to the prior art for a number of years. To further aid the protection of the document, some in the prior art have used a substantially transparent material to overlay the document while the document was secured to the springboard or clipboard. Others in the prior art have developed transparent containers for protecting the document while enabling visual inspection thereof. These containers have been made of rigid and flexible plastic materials with various types of closures for securing the document within the container.
For a number of reasons, the aforementioned containers have not found widespread use in the art. In general, these devices were constructed of a number of parts which required assembly to produce the container device. Finally, these prior art devices did not provide means for enabling the visual inspection of both sides of the document contained therein, nor even if the advantages inherent in each of the references were to be combined, the claims of the present invention would not be met.